The recent miniaturization of electronic devices calls for the development of electric batteries of reduced weight and, yet, with high performance characteristics. Conductive polymers are attracting attention as electrode active materials for such batteries and a large number of electrically conductive polymers including polyaniline, polypyrrole and polythiophene have heretofore been developed. These polymers are generally synthesized from the corresponding monomers by electrolytic or chemical oxidative polymerization. Since, up to the present time, aniline, pyrrole, thiophene and their derivatives have been chiefly used as starting monomers for such conductive polymers, the conjugated structure of the backbone chain of such polymers other than polyanilines which contain nitrogen atoms consists of carbon-carbon double bonds. Attempts have been made to improve the stability and electrical conductivity of polymers by introducing azo groups, as new structural moieties, into the backbone conjugated system consisting of carbon-carbon double bonds and, as a specific example, polyazophenylenes have been synthesized but none have proved to have characteristics surpassing the polymers in the carbon-carbon double bond series.